You can also use the Once your download of Cassandra finishes, move the file to whatever directory you\u2019d like to use for testing Cassandra. Then uncompress the file (whose name will change depending on the version you\u2019re downloading):<\/p>\n Then switch to the new Cassandra bin directory and start up Cassandra:<\/p>\n Now that you have Cassandra running, the next thing to do is connect to the server and begin creating database objects. This is done with the Cassandra Query Language (CQL) utility. CQL is a very SQL-like language that lets you create objects as you\u2019re likely used to doing in the RDBMS world.<\/p>\n The CQL utility (cqlsh) is in the same bin directory as the cassandra executable:<\/p>\n [cqlsh 2.3.0 | Cassandra 1.2.2 | CQL spec 3.0.0 | Thrift protocol 19.35.0]<\/p>\n Cassandra has the concept of a keyspace, which is similar to a database in a RDBMS. A keyspace holds data objects and is the level where you specify options for a data partitioning and replication strategy.<\/p>\n For this brief introduction, we\u2019ll just create a basic keyspace to hold some example data objects we\u2019ll create:<\/p>\n Now that you have a keyspace created, it\u2019s time to create a data object to store data. Because Cassandra is based on Google Bigtable, you\u2019ll use column families \/tables to store data.<\/p>\n Tables in Cassandra are similar to RDBMS tables, but are much more flexible and dynamic. Cassandra tables have rows like RDBMS tables, but they are a sparse column type of object, meaning that rows in a column family can have different columns depending on the data you want to store for a particular row.<\/p>\n Let\u2019s create a base table to hold employee data:<\/p>\n The column family is named emp and contains four columns, including the employee ID, which acts as the primary key of the table. Note that a column family must have a primary key that\u2019s used for initial query activity.<\/p>\n Let\u2019s now go ahead and insert data into our new column family using the CQL INSERT command:<\/p>\n Notice how Cassandra\u2019s CQL is literally identical to the RDBMS INSERT command. Other DML statements are as well:<\/p>\n Querying data uses the familiar SELECT statement:<\/p>\n However, look what happens when you try to use a WHERE predicate and reference a non-primary key column:<\/p>\n In Cassandra, if you want to query columns other than the primary key, you need to create a secondary index on them:<\/p>\n Installing DataStax OpsCenter on Mac involves working through the following steps in a terminal window:<\/p>\ncurl<\/code> command on Mac to directly download the files to your machine. For example, to download the DataStax Community Server, you could enter the following at terminal prompt:<\/p>\ncurl -OL http:\/\/downloads.datastax.com\/community\/dsc.tar.gz<\/code><\/p>\nInstall Cassandra<\/h3>\n
tar -xzf dsc-cassandra-1.2.2-bin.tar.gz<\/pre>\n
robinsmac:dev robin$ cd dsc-cassandra-1.2.2\/bin\nrobinsmac:bin robin$ sudo .\/cassandra\nrobinsmac:bin robin$\u00a0 INFO 14:49:57,739 Logging initialized\nINFO 14:49:57,750 JVM vendor\/version: Java HotSpot(TM) 64-Bit Server VM\/1.6.0_35\nINFO 14:49:57,750 Heap size: 2093809664\/2093809664\nINFO 14:49:57,751 Classpath:\n.\n.\nINFO 14:49:59,208 Completed flushing \/var\/lib\/cassandra\/data\/system\/schema_columns\/system-schema_columns-ib-2-Data.db (210 bytes) for commitlog position ReplayPosition(segmentId=1362167398602, position=53130)<\/pre>\n
robinsmac:bin robin$ .\/cqlsh\nConnected to Test Cluster at localhost:9160.<\/pre>\n
Use HELP for help.\ncqlsh><\/pre>\n
cqlsh> create keyspace dev\n... with replication = {'class':'SimpleStrategy','replication_factor':1};<\/pre>\ncqlsh> use dev;\ncqlsh:dev> create table emp (empid int primary key,\n... emp_first varchar, emp_last varchar, emp_dept varchar);\ncqlsh:dev><\/pre>\n
cqlsh:dev> insert into emp (empid, emp_first, emp_last, emp_dept)\n... values (1,'fred','smith','eng');<\/pre>\n
cqlsh:dev> update emp set emp_dept = 'fin' where empid = 1;<\/pre>\n
cqlsh:dev> select * from emp;\nempid | emp_dept | emp_first | emp_last\n------+----------+-----------+----------\n1 |\u00a0\u00a0\u00a0\u00a0\u00a0 fin |\u00a0\u00a0\u00a0\u00a0\u00a0 fred |\u00a0\u00a0\u00a0 smith<\/pre>\n
cqlsh:dev> select * from emp where empid = 1;\nempid | emp_dept | emp_first | emp_last\n------+----------+-----------+----------\n1 |\u00a0\u00a0\u00a0\u00a0\u00a0 fin |\u00a0\u00a0\u00a0\u00a0\u00a0 fred |\u00a0\u00a0\u00a0 smith\ncqlsh:dev> select * from emp where emp_dept = 'fin';\nBad Request: No indexed columns present in by-columns clause with Equal operator<\/pre>\n
cqlsh:dev> create index idx_dept on emp(emp_dept);\ncqlsh:dev> select * from emp where emp_dept = 'fin';\nempid | emp_dept | emp_first | emp_last\n------+----------+-----------+----------\n1 |\u00a0\u00a0\u00a0\u00a0\u00a0 fin |\u00a0\u00a0\u00a0\u00a0\u00a0 fred |\u00a0\u00a0\u00a0 smith<\/pre>\n
Installing and using DataStax OpsCenter<\/h3>\n
\n
tar \u2013xzf<\/code>) in the directory you want to use for OpsCenter.<\/li>\n.\/setup.py<\/code> script.<\/li>\n.\/opscenter &<\/code> from the bin directory.<\/li>\n.\/setup 127.0.0.1 127.0.0.1<\/code>.<\/li>\n.\/datastax-agent<\/code>.<\/li>\n![\"dsc](\"https:\/\/i0.wp.com\/www.datastax.com\/wp-content\/uploads\/2012\/01\/dsc-osx6.jpg?w=623\")
\n![\"dsc](\"https:\/\/i0.wp.com\/www.datastax.com\/wp-content\/uploads\/2012\/01\/dsc-osx7.jpg?w=623\")
<\/p>\nConclusion<\/h3>\n